Effect of V/C on thermal fatigue property of the cast hot-work die steel

Thermal fatigue property of the cast hot-work die steels with different V/C was investigated with the self-restricting test method. The thermal fatigue behavior of the cast hot-work die steel and H13 steel was also contrasted. The results indicate that the thermal fatigue of the cast hot-work die steel is high-cycle thermal fatigue, therefore the main factor affecting thermal fatigue resistance is thermal strength and thermal stability. With V/C rising, thermal fatigue resistance increases first and then decreases. As V/C is 3.0, thermal stability and thermal strength of the cast hot-work die steel are improved because of dispersed VC in the microstructure, thus thermal fatigue resistance reach maximum. It is found that the thermal fatigue property of the cast hot-work die steel is better than that of H13 steel.